Radioreceiver



Aug. 15, 1933. c. M. DALY 1,922,279

RADIORECEIVER Filed Oct. 2, 1929 2 Sheets-Sheet l Sheets-sheaf 2 C. M. DALY RADIORECEIVER Filed Oct. 2, 1929 nun n n a nfii Aug. 15, 1933.

frequencies of radio transmission or broadcasting by condensers 23 placed across the secondaries 24 of the coupling devices and 16, bein; connected to the latter by wires 26 at one side and at the other side, as diagrammatically indicated in Fig. 1, by wires 26 connected to the common wire 12, the latter being connected by wires 27 to the secondaries 24.

In the type of radio-receiving set illustrated, the set may be rendered inoperative by interrupting the supply of current 1 which heats the filaments ll of the valves 10. This is done by placing a switch 28 in series with the battery or other source 14 and the feed wire 13 leading to the filaments, so that by closing the switch,

current causes the filaments 11 to be heated,

and likewise when the switch is opened the filaments cool off. This switch, as heretofore provided, was manually operative by a finger-piece or lever provided on the control panel of the set. I

This'type of set is so well known that it requires no further illustration or description. It sufiices to say that'the output-volume of the set represented by the volume of sound emitted from the loud-speaker 22 is controlled by a potentiometer P inserted between the grid 29 of the first valve 10 and the negative filament wire 12 being connected to the grid by a wire 30 and to the negative filament 12 by a wire 31. The form of potentiometer herein illustrated constitutes a part of the present invention will be described below.

It is also noted that for convenience in operation and to reduce the cost of making the set, the three or more condensers 23 are balanced relatively and ganged so as to be operable by a single operating device. ment is illustrated in Fig. 2, in which stator plates 32 of the condensers 23 are placed one behind. the other and are supported by a common supporting frame 83, while the rotor plates 34 are mounted on a common shaft 35' having bearings 36 in the end plates 3'! of the frame 33. The plates 34, being all connected together in" electrical contact with the shaft 35, require ,only one wire 26 .to connect them to the wire 12 to which the secondaries 24 are connected by the wire 27, and this wire 26 has a pig-tail or other flexible connection 38 with the shaft 35.

The forward end of the shaft is provided with an operating knob 39 by means of which. the shaft may be turned tovary the setting of the condensers, and this setting maybe indicated by a dial 40 secured to the operating shaft 35.

It should be understood that the specific type of condenserarrangement shown and above de scribed is merely for illustrative purposes and ,that any other suitable type may be employed.

Moreover, the handle or knob may be mounted independently of the shaft 35 any ,motion transmitting train desired may beprovided between the handle and shaft without departing from the spirit of the present invention.

As stated above, one of the many objects of the present invention is to provide a single con trol device for tuning-in and for controlling the output volume oi the .set. To carry out this object, the present invention couples the pot tionometer- P and tuning condensers 23 in such a way that, for each predetermined increment of movement of the condensers, the potentio meter. moves through its complete cycle from maximum to minimum.

Accordingly, as shown herein,..'the condenser tact so that the disk engages the resistor.

This arrangev shaft 35 is provided with a gear 41 meshing with a gear 42 secured to a disk 43 carrying the resistor of the potentiometer and rotating with a shaft 44; having a bearing 45 which is secured to the end-piece 37 of the condenser frame, so that the movements of; the disk 43 of the potentiometer and the rotor plates 34 of the condenser will be in coordination.

The specific type of potentiometer P illustrated he.ein comprises, as stated, the disk 43. This is made of insulating material and carries on its face resistance material 46. This may be in the form of a high resistance wire, or of carbon in block or deposited form, electrically connected by a member 4.7 to the shaft a l on which the disk is mounted. Spaced from the disk 43 and member, 47 by an insulating washer 48 is a flexible metal disk 49 which overlies the resistance element 46 and which is held in position to rotate with the disk 43 and shaft 44 a washer 50 interposed between the metal l9 and a head 51 on the shaft 44.

Only one point of the metal disk 49 is at any time held in contact with the resistor 46, and this is done by means of a roller 52 mounted on ashaft 53 rotatably mounted in a bearing 54. The roller 52 is located in such position with relation to the disks i3 and 49 that it causes the flexible disk as to be bowed inwardly at its point of con- When the shaft is rotated, the successive portions of the'disk 49 are pressed against the resistor 46, and thus the disk 4.9 is connected with the resistor a point closer to or farther from the point at which the memberd'? is connected and this takes place without any rubbing or frictional contact between the plate 49 and the resistor 46. The shaft is and member 47 are connected to the wire 31 which, by reference to Fig. 1, will be seen to lead to the common wire 13, while the roller connected by'the wire 30 to the grid 29 of the first-valve 10.

-The ratio of the gearing l-ll2 between the operating shaft 35 and the potentiometer shaft 44 may be such for one or two degrees of movement of teshaft 35, the'disks 4349 0;?

. potentiometer will make one complete revo- However, in order-that an excessively ratio will not be needed, the potentiometer is so arranged that a fraction of a complete revolution of the disks 43-49 is all that is needed to shift thepotentiometer from maximum to minimum positions. For this purpose, the electrical resistance of the resistor 46 is made of h gh value and the member- 47 is pro vided with a plurality of arms 55, there being eight in the specific embodiment of the invention shownherein, or connection to the resistor at eight equally spaced places in its length diagrammatically in Fig. 1, (the brush 5'7 substitu ing for the point of contact of the plate 49 with the resistor) no resistance is added to the ci cuit by the resistor 46. When, however, the dislr l3 moved in-either direction from that shown in 1, resistance is added to the'circuit inproportion-to the amount of movement maximum' resistance is obtained when the con tact point (brush 57) is mid-way between the pointsof connectionor the arms 55 withthe resistor '46, as shown inFig. 5. The continued movement of thedisks 43 and 49 in itherdirection from this point causes, the "amount of resistance placed in the circuit by the resistor 46 to decrease. It will thus be seen that for every 22 /6 of movement of thedisk 43;the effective resistance of 'theresistor 46 is changed from arbitrarily to exemplify the invention, and it should be understood thata greater or lesser number of connected points and a vastly different ratio of gearing may be used if desired. The

specific'arrangement'employed would depend largely upon the sensitivityof the set and the proximity of one station to another in the band offrequencies within whi'chfithe set is designed to operate i As above describedi it will be seen'that since. complete volume control may. be obtained with three degrees of movement of the operating shaft 35, with certain-"typesof sets it is possible to. remain fairly well tuned on a station while addusting within these three degrees of movement I to varythevolume.

As stated above, anotherobjectof the present invention is to'provide a single means for tuning and/or controlling the volumeof 1 the set, and'forrendering the set operative and'inoper ative so that but solely one operating member need be provided on the control panel of the set.

To accomplish this; the present invention pro vides a disk 58 on the operating shaft 53 having one or more cams 59 locatedinposition to engage a movable arm 60of the switch 28 which, as stated above, is interposed in the current supply circuit of the set.

In the form shown, where the operating shaft i .35, moves between fixed limits of movement of approximately 180, there are two of these cams 59 located substantially diametrically oposite each other. These cams are so placed on the shaft that when the shaft has been turned to the position where the rotor plates 34 are completely removed from between the stator plates 32, a slight further movement of the shaft will cause one of the cams 59 to raise. the arm of the switch, from the stationary arm 61 Jthereof and open the current supply circuit.

The other cam 59 is so placed that when the rotor plates are completely located between the stator plates, slight farther movement will cause I that cam to raise the movable arm '60 of the switch. With this arrangement, when it is desired .to shut off the set, the knob 39 on the shaft 35' is rotated in either direction to the limit of its movement; whereupon the set is ren ,dered inoperative by the opening of the current supply circuit, and when it is desired to again i use the set; the set is automatically made operative by the supply circuit when the knob 39 is rotated to tune in the desired station. of

course, it should be understood that where a set is operated from house current, in which case rectifiers and transformers are used instead of batteries, the switch 28 opens and closes the current supply circuit transformers.

The present invention also embraces the operation of the single control from a remote point to the rectifiers and To accomplish this in a simple expeditious manner; the present invention provides a motor 62 which drives the operating shaft 35. For

this purpose, the motor may be provided with a worm 63n1eshingwith a worm-wheel 64 carried by ashaft 65 mounted in bearings 66 and having a spring actuated'clutch disk 6'7 engaging a driving disk 68 on the operating shaft 35, the clutch 67-63 being provided so that the operating shaft may beadjusted in-spite of the fact that the remote-point, so that it'may be reversible from thatpoint, three wires 71, '72 and 73 are led from the motor to a station Sfiwhere a switch 74 is provided. This switch has an actuating member or button '75 connected to the common return wire 73 and movable so as to either engage a contact 76 on the wire '71 or a contact I'lon the wire '73 to cause the motor to operate in either onedirection or the other. Thus, by moving the switchhandle 75 in one direction, the operating shaft 35 will be caused to move say in clockwise direction. This will cause the rotor plates 34 to move from between the stator plates 32 and tune-ina station. When the station has been tuned in, the shaft 35 may be operated by the *motor either forwardly or backwardlyto control must be operated in the other direction.

As soon asthe shaft 35 begins tomove from one of its extreme positions, the switch 28 will be closed by the movement of the cam59 away from the operating arm 60 of theswitch. When it is desired toturn the set off; the handle 75 is held depressed sufficiently long to cause the shaft 35 to reach the limit of its movement in the direction operated, at which time the switch 28 is opened automatically by the engagement of the cams 59 on the motorand drive shaft 35.

Variations, and modifications may be made within the scope of this invention and portions of the improvements may be used withoutothers.

Having thus described the invention, what is claimed as new and for which it is desired to obtain Letters Patent, is: .1. In a radio-receiving set, an operating device; a plurality of condensers rotatedby the so that the set may betuned-in andhave its a volume controlled from one or more points in t t the house; maximum to minimum and gradually so as the movement takes place. i 1 i r With thisprovision, it will be seen that'it is only-necessary to have a gear ratio of 10:1 between the potentiometer shaft 44andthe condenser shaft 35, and that for everythree degrees of movement of the condenser shaft, the poten- "tiometer'is adjusted through itscomplete range. The number of arms 55 or common connecting points of theresistor 46, andthe ratio of the gearing above referred to, has been selected operate, the user would know that the handle '25 rotation of said device to tune the set to the fre- V Y quency of the signal desired to be received; a, variable resistor having a movable member. for

adjusting the resistance ina portionof the cir-.

the volume of the signal received; and means 7 connecting the movable member of the resistor to said operating device whereby movement of the latter adjusts the condensers and operates the movable, member of the, resistor through a complete; cycle of volume control from maximum to minimum for each one ofa large number, of small adjustments of the condensers.

2. In a radio-receiving set, an operating device; a plurality of condensers rotated by the rotation of said device to tune the. set to the frequency of the signal desired to be received; a variable. resistor having a movable; member for adjusting the resistance in a portion of the circuit of the set to optionally increase or decrease the volume of the signal received; means connecting the movable member to said operating device whereby movement of the latter adjusts the condensers and operates the movable member of the'resistor through a complete cycle of volume control from maximum to minimum for each one of a large number of small adjustments of the condensers; a motor for operating said device; and a remote control circuit including a switch member for operating the motor.

3. In a radio-receiving set, anoperating device; a plurality of condensers rotated by the rotation of said device to tune the set to the frequency of the signal desired to be received; a variableresistor having a movable member for adjusting the resistance in a portion of the circuit of the set to; optionally increase or decrease the volume of thesignal received; means connecting the movable member to said operating device whereby movement of the latter adjusts the condensers and operates the movable member of the resistor through a complete cycle of volume control from, maximum to minimum for each one of a large number of small adjustments of the condensers; a motor for operating said device; a remote control circuit including by said operating device for operating said main switch.

4. In a radio-receiving set, tuning means for. adjusting the set to the frequency of. the signal desired to be received; volume control means other than the tuning means for optionally increasing or decreasing the volume of the signal received; and a single operating device for adjusting the tuning means'and for adjusting the volume control means through a complete cycle of volume control from maximum to minimum for eachone of a large number of small adjustments of the condensers.

of the setbetweenmaximum and minimum volumes; and means interconnecting the tuning means and volume control means for simultaneous movement and in such relative amounts that the volume control means moves through its complete range between maximum and mini mum volume positions for each of a plurality of relatively small predetermined increments of movement of the tuning means, within which increment of movement of the tuning means the latter maintains the set in tune with the particular; frequency of a station being received.

6. In a radio-receiving set, an operating device; a plurality of condensersrotated by the rotation of. said operating device to tune the set to the frequency of the signal desired to be received; a variable resistor having a movable member for adjusting the resistance in a' portion of the circuit of the set to optionally increase or decrease the volume of the signal received; and gearing connecting the movable member of the resistor to said operating device whereby movement of the latter adjusts the condensers and operates the movable member of the resistor through a complete cycle of volume control from maximum to minimum vfor each one of a large number'of small adjustments of the condensers. I

- 7. In a radio-receiving set, tuning means for adjusting the setto receivesignals of any frequency from a given range of frequencies to tune in a station, volume control means for varying the output of the set between maximum and minimum volumes; a main control switch for connecting the set to sources of 'electro- I control means for the motor including motor reversing means for causing the tuning means to be operated at will in either direction.

CHRISTOPHER M. DALY. 

